Add Function.overArgs function

pierredup · pierredup · commit 16f9a04fcc91 · 2018-12-10T23:41:44.000+02:00
diff --git a/src/Function/overArgs.php b/src/Function/overArgs.php
@@ -0,0 +1,72 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the SolidWorx Lodash-PHP project.
+ *
+ * @author     Pierre du Plessis <open-source@solidworx.co>
+ * @copyright  Copyright (c) 2017
+ */
+
+namespace _;
+
+use function _\internal\arrayMap;
+use function _\internal\baseFlatten;
+use function _\internal\baseRest;
+use function _\internal\baseUnary;
+
+/**
+ * Creates a function that invokes `func` with its arguments transformed.
+ *
+ * @static
+ * @memberOf _
+ * @category Function
+ *
+ * @param callable   $func       The function to wrap.
+ * @param callable[] $transforms The argument transforms.
+ *
+ * @return callable the new function.
+ *
+ * @example
+ * <code>
+ * function doubled($n) {
+ *   return $n * 2;
+ * }
+ *
+ * function square($n) {
+ *   return $n * $n;
+ * }
+ *
+ * $func = overArgs(function($x, $y) {
+ *   return [$x, $y];
+ * }, ['square', 'doubled']);
+ *
+ * $func(9, 3);
+ * // => [81, 6]
+ *
+ * $func(10, 5);
+ * // => [100, 10]
+ * </code>
+ */
+function overArgs(callable $func, array $transforms): callable
+{
+    return baseRest(function ($func, $transforms) {
+        $transforms = (count($transforms) == 1 && \is_array($transforms[0]))
+            ? arrayMap($transforms[0], baseUnary('\_\internal\baseIteratee'))
+            : arrayMap(baseFlatten($transforms, 1), baseUnary('\_\internal\baseIteratee'));
+
+        $funcsLength = \count($transforms);
+
+        return baseRest(function (...$args) use ($funcsLength, $transforms, $func) {
+            $index = -1;
+            $length = \min(\count($args), $funcsLength);
+
+            while (++$index < $length) {
+                $args[$index] = $transforms[$index]($args[$index]);
+            }
+
+            return $func(...$args);
+        });
+    })($func, $transforms);
+}
diff --git a/tests/Function/OverArgsTest.php b/tests/Function/OverArgsTest.php
@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the SolidWorx Lodash-PHP project.
+ *
+ * @author     Pierre du Plessis <open-source@solidworx.co>
+ * @copyright  Copyright (c) 2017
+ */
+
+use PHPUnit\Framework\TestCase;
+use function _\overArgs;
+
+class OverArgsTest extends TestCase
+{
+    public function testOverArgs()
+    {
+        function doubled($n)
+        {
+            return $n * 2;
+        }
+
+        function square($n)
+        {
+            return $n * $n;
+        }
+
+        $func = overArgs(function ($x, $y) {
+            return [$x, $y];
+        }, ['square', 'doubled']);
+
+        $this->assertSame([81, 6], $func(9, 3));
+
+        $this->assertSame([100, 10], $func(10, 5));
+    }
+}
